I have a lot of question and I wanted to run what I think I've learned by everyone to make sure I am right.In need a bosch type relay with leads reading 30, 85, 86, 87, 87a.

For breaking i need a 5w 0.47 ohm resistor?

My wire should be 14 awg minimum?

Almost any "Normally Open" switch will work for the turbo button?

I need to add fuses as close to the batteries as I can. But what size, 30 amp? Can I go smaller to be safer?

Will the brake still work on a hill or will the resistor keep it from really braking?

I have a three working used red 6v batteries. Will they work or will their built in protection kick in when I don't want it to?

This I assume should be in-front of the foot throttle and Fwd/Rev switches.

Am I missing anything?

Perhaps a man has plenty of food and things. He sees that his brother needs some. If he does not want to help his brother, does he love God? My children, we must not only talk about loving people; we must show we love people by what we do for them. We must really love them.

Divinar wrote:You've got it. This diagram will even work with the cheaper 12v relay. Although they make 6v versions

The diagram is showing 12v on the coil. No need for a 6v.______________________________________________________________________________________________________

coulter's wrote:I have a lot of question and I wanted to run what I think I've learned by everyone to make sure I am right.In need a bosch type relay with leads reading 30, 85, 86, 87, 87a.

Yes, with a 30/40 amp contact rating.

For breaking i need a 5w 0.47 ohm resistor?

It is not needed, but makes the breaking softer and reduces gear box stress.

My wire should be 14 awg minimum?

I always recommend 12gauge as a minimum, but some toys come wired with 14 gauge and work fine.

Almost any "Normally Open" switch will work for the turbo button?

Yes, the relay coil draws very little current. The original designed called for a 'Normally Open Momentary Closed' push button switch mounted on the steering wheel. Mounting a ON/OFF toggle or rocker style switch to the dash would work as well, but it would work like a High/Low speed selector not a temporary 'turbo' boost.

I need to add fuses as close to the batteries as I can. But what size, 30 amp? Can I go smaller to be safer?

Yes, a 30 amp. With proper wire gauge using a 30 amp fuse is safe. Anything less will probably prematurely trip/blow.

Will the brake still work on a hill or will the resistor keep it from really braking?

a 5 watt 0.47 ohm resistor should 'hold' on moderate inclines.

I have a three working used red 6v batteries. Will they work or will their built in protection kick in when I don't want it to?

I never used them, but I read several threads were the internal breaker caused problems...I think it was mostly when using them on 18v setups. Most members use aftermarket 6v 12ah batteries. If you decide to use the stock batteries. Placing external fuses on them would just be redundant.

Perhaps a man has plenty of food and things. He sees that his brother needs some. If he does not want to help his brother, does he love God? My children, we must not only talk about loving people; we must show we love people by what we do for them. We must really love them.

I started thinking about how I would avoid one battery running down more than the other. Then I came up with the idea of constantly staying 12v, and then the turbo button will change the motors from series to parallel. I would think someone has done this before.

I got the idea from looking at this schematic that Jparthum posted.

Does anyone have any thoughts?

Last edited by coulter's on Sat Dec 03, 2011 4:04 am, edited 2 times in total.

Perhaps a man has plenty of food and things. He sees that his brother needs some. If he does not want to help his brother, does he love God? My children, we must not only talk about loving people; we must show we love people by what we do for them. We must really love them.

I liked my last plan but I started to read that some people get stuck a lot when the wheel motors are in series. My kid will be on grass most of the time. And I came up with a new solution today.I will use two relays and a momentary switch to switch the batteries from series to parallel.

I do have a problem though, is there a way i can have the relays powered by the two batteries in series, and at the same time have them switch the batteries to parallel? I might need a separate battery here.

Any ideas?

Perhaps a man has plenty of food and things. He sees that his brother needs some. If he does not want to help his brother, does he love God? My children, we must not only talk about loving people; we must show we love people by what we do for them. We must really love them.

coulter's wrote:I do have a problem though, is there a way i can have the relays powered by the two batteries in series, and at the same time have them switch the batteries to parallel? I might need a separate battery here.

Any ideas?

You would need a separate battery or you could use 6v relays. The draw back to 6v relays...If your adding lights or any other 12v accessories, you would need a fixed 12v source to power those as well.

Switching the motors from series to parallel is how most of the manufactures of these toys wire there shifters to control the speed. Most members that would like to add a high/low speed selector, just replace the original wiring harness with a 12v PW harness and shifter off a donor toy.

Last edited by 12vwiz on Sun Dec 04, 2011 1:17 pm, edited 1 time in total.

I'm going to go 12v on my son's Super 6 Lightning McQueen soon and want to use the button method with two 6v batteries. I've studied this diagram and pretty much have it, but am not sure about one thing:

Where I've circled in red, is the resistor wire tied into the wire from the battery or is that just where the two "lines" in the schematic overlap? And is that resistor already in the factory harness? (Oops...guess that's TWO things)

h-bomb wrote:Where I've circled in red, is the resistor wire tied into the wire from the battery or is that just where the two "lines" in the schematic overlap? And is that resistor already in the factory harness? (Oops...guess that's TWO things)

It is a connection point. In the drawing... both the resistor and the turbo button require a negative source. This is where the author is showing the connection being made , but it could be made anywhere on the negative side. The larger line is the main negative wire from the batteries to the motors. He just taped the negative source their instead of running the wires back to the battery negative.

The brake shunt line could have a resistor installed or it could use a direct wire to the foot pedal instead, It all depends on the model you have. Some have it and some don't. The resistor just determines the pressure that the brakes applies. A direct wire being the max breaking and a resistor with a increasing value lowers the breaking pressure.